1. Field of the Invention
The present invention relates to an extendable pivot shaft mechanism of a camera for pivoting a rotatable grip on a camera body, and also relates to an extendable pivot shaft mechanism incorporated in various apparatuses including a camera.
2. Description of the Related Art
A conventional mechanism (extendable pivot shaft mechanism) for connecting two devices with each other to allow the two devices both to rotate about a rotational axis relative to each other and to move along the rotational axis relative to each other is difficult to construct so as to operate smoothly without increasing the size of the mechanism. For instance, the assignee of the present invention has found that providing a camera body with a rotatable grip capable of both rotating about a rotational axis and moving along the rotational axis relative to the camera body via the extendable pivot shaft mechanism improves the operability of the camera. However, in precision apparatuses, especially in precision equipment such as a camera which is provided with an extendable pivot shaft mechanism for pivoting a rotatable grip on a camera body, smooth operation and miniaturization of the extendable pivot shaft mechanism are required. In addition, it is desirable that an electrical connecting elements (e.g., lead wires or a flexible PWB (printed-wiring board)), for electrically connecting two devices with each other such as a camera body and a rotatable grip pivoted on the camera body, be installed through the extendable pivot shaft mechanism for the purpose of reducing the space that the electrical connecting elements occupy. However, it is difficult to install such an electrical connecting elements through a conventional extendable pivot shaft mechanism, e.g., disclosed in Japanese laid-open patent publication H06-98210.